Ask HN: Any finance topics you're interesting in learning about?

Background: my co-founder and I are in the process of preparing to launch a business around financial modeling software that we've built. We discussed the idea of writing a book (or a series of articles) that we could give away for free on finance topics (e.g., cash flows, accounting, budgeting, NPV modeling, etc.). This would hopefully allow us to 1) provide a generally useful document to anyone who downloads it and 2) demonstrate the capabilities of our software. I've come up with a list of topics that I plan on writing about, but thought maybe I could get some ideas from HN readers to augment my own.

So, are there any topics that you are interested in reading about / learning about related to finance?

Also (on a separate, but related note): once finished with the book/articles, is it appropriate to submit it to HN? That is, I hope (and expect) that it will be useful to anyone even if they don't use our software, but obviously one of the primary goals would be to help sell software too.

Thanks for your feedback!